I've been thinking about upgrading mine for ages and ages. Thing is, to do so would cost around £500. It may not look different to my old one, but it has -
500w brushless motor.
Larger steppers with manual controls.
Limit switches (so I never have to hear the sound of grinding gears again)
A stop button.
Larger rails (12mm vs 10mm)
All metal body and motor holder (plastic now)
48v PSU vs 24 now.
New controller board that can take 48v (so I would need a new one, as even a higher RPM motor nearly melted it)
And so on.
I got 5% off, so it cost me £246. I will be able to use my 40cm extension (so it will be a 3040), but the rails will need making by my mate. Existing rails are 10mm, but the centre screw part remains the same. Oh and the side extensions of course.
I will put the old one back to stock, and can run simple slower jobs on it.